nukblazi

a little oversteer, great for autocross, bad for the track.

I also don't understand how it provides "high speed stability" as stated by LARS. Any sort of high speed turn, the **** of the car should be looking to come around on you. Even at HWY speeds.

mdp c230k

Running very high pressures like 45+psi makes the tire dribble like a basketball on bumps! No high speed control on rough surfaces and more likely to get punctured. With a stock setup run 32f and 34r to start then adjust from there. With a rear sway bar upgrade flip the numbers around so the rear has lower pressure. Thats about 30 years worth of experience in a nutshell.

hobie

I'm with mdp. Although 30 years is pushing the flat rate, even at a MBstore!

Chat>comments? Yeah, nice boat, and I have no idea. Sounds like your set how you like it, but are you maximzing all those cool parts? Maybe you could be faster with the same balance. If your tires were the same size and type, I'd start at 36f/35 to account for the cars weight distribution. Have 1/4 tank of gas. Next I'd set the ride height even 1/2" above bottom. Set shock stiffness even and at middle of adjustment. Drive it (warm tires) and adjust/replace only sway bars until you get the balance you like. How close to adjustment limits are the bars? If one is near limit, bring it back toward middle and then work the other variables. Once you balance the chassis then the last step is tire pressure. The wild card are the tires. You might tune it and find that a new set of tires puts you back at square one. Did you deliberatly put softer rubber on the front? I think our chassis is good enough to avoid that solution.

hobie

afterthought: some prefer to start tuning without any sway bars on/attached if they have an array of springs available. For kicks you might want to remove the bars and take it for a spin to see if Carlsson did thier homework.

nukblazi

mdp- I was talking about optimal performace from the tires, not streetabiltiy. From the optimal point, drop a lot of pressure for the street as you would never be pushing it to the limits, or at least shouldn't be.

For my tires 45lbs is perfect, pushed to the bleeding edge of the tire without rolling onto the sidewall, and utilizing the cornering stability built into the shoulder blocks.

I am still perplexed regarding the recommendations of MB, and inducing oversteer for high speeds.

hobie

hey Nuk, yeah your on for AutoX. Skipping the tuning minutia, how does it feel? Big time? What's next? Is it hooking up?

Wheens

If anyone wants to get a great hands on lesson in oversteer, log a little spirited seat time in a 911. The 911 is famous for TTO..trailing throttle oversteer.

Inexperienced 911 drivers will enter a turn under throttle, ease off to brake at/near the apex, and suddenly experience the rear end coming around bigtime!

Proper technique is brake early and power your way thru the curve...don't lift off the throttle!!! You have to accelerate your way thru the turn.

What happens is when you lift off the throttle to brake you unload the rear end. Since this is where the majority of the car's weight is(rear engine), the unloading causes the rear to get squirrilly.

Freeway exit ramps are disasters waiting to happen if you don't know what you are doing.

Matt230K

Wheen, while I have no doubt that it would be easy to get the 911 to swap ends over some other cars, this particular trait was common on the older 911's. Nowadays, they are much more balanced, although I'm sure if you wanted to, you could get it to do the same thing. And tires are much better now, so you would have to go much faster to reach the traction limit of the tires.

Wheens

Matt
I can only speak to 911's up to the 993.
I've owned 4 of the beasts, logged more than 250k miles in them and enjoyed every minute of their quirky behavior.

I'm sure the newer ones are more sophisticated in their suspension, etc.

BTW, my new C320 coupe w/manual is nearly as much fun, although I'm sure I won't be flogging it like I did the 911s....call it old age

Matt230K

Yeah, I've heard the closest you can get to off throttle oversteer nowadays is in the GT2, since it is rear wheel drive only, instead of the turbo's all wheel drive.

lars

I drive another prime TTO device, a Lotus Europa. "Lotus Makes You A Better Driver" was one of their marketing slogans and, by golly, they were right. I had to learn in order to keep the car in one piece.

nukblazi

Auto-x feels awesome. Even modless. Nothing better then the look on a M3 owners face after he's said, "That's not an auto-x car!" and you just handed him his *** back by two seconds.

The car hooks up real nice. I had been running 245/40's on the rear stock C7 wheels. It helpedb. I have corrected the two initial mistakes I had been making. Over driving hairpins, and over inflating my rear tires. (tire pressure, tire pressure, tire pressure!) Since then, it's been two trophies in two events. I am up a few seconds on my other auto-x'es, based on the comparision of my time to FTD. The past two events where friday events, so the participation was smaller, but points are points, and I know I am doing better.

Next? A full cage a a rookie license via NASA. Speaking to SCCA to get the car classed for prof. series shiet! In the mean time, many more mods, and more auto-x'es. There are also two HPDE's this month I am set up for. hehehehe

I love the way the coupe drives. "Tommy", another MBWorld member has seen me drive. I think the coupe is great for Auto-x, he thinks I am doing well despite the car... I have no idea who is right, but I am having mad fun.

Some other people agree with Tommy, others have begun their search for the right M111 coupe... either way, something good is happening.

I drove the car that hit FTD at the last event. It is a nice RX-7 that belongs to a instructor. I wasn't off his mark, but not FTD, and it wouldn't have counted anyway. However, strange car, one run, I was pleased.

So, you seem to know your stuff. What <i>are you!</i> up to? Is it in your coupe? Does it having anything to do with Tire Pressures?

The coupe is fun to drive, it just needs somethings. Like the LTW Flywheel from KLEEMANN I installed today. I am still adjusting, but it is awesome feeling wise. A huge difference.

Lynn

Speaking of the perfect coupe for X-cross, Plaza Motors here in St. Looie has a used 2002 with NO options on the used lot.

nukblazi

Nice-

If I didn't trust my coupe so much, (break in, work history) I would be looking to trade it in for that one. That's awesome. Why do you pick it up as a spare Lynn?

Lynn

If I had the money, I would buy it and do the some of the same things with it as you are doing with your car.

nukblazi

Ahhhh-

If I had the money I would buy it and make it a strictly track car. Alas, I can't...

I can tell you I will be posting a few pictures and a complete write up, dyno, 0-60 times, and 1/4 mile time from the flywheel soon, but first impressions...

AWESOME

Around town it gets some getting used to, you do lose some streetability around town, but the feel from it accelerating and downshifting is so much better. It feels the way it should of. Just as Brandon stated, there are vibrations. They are coming from the gearbox not the modification.

If you were willing to knowingly sacrafice some drivability, the mod is worth it just for today's trott around the area. I've put 22 miles on the assembly. I love it.

I still can't wait to get everything installed and the TOYO RA-1s! Going to be another PSI learning experience...

Lynn

I believe that you are now in SCCA Street Modified. Is that correct? Are the Toyos R compound? If so, they are not legal in SM.

DiamondNoir2K5

What do you C230 Sedan owners keep your tires inflated to? Mine came from the dealer at 32 front 36 rear, which is 4psi over the door sill label's recommendations of 28 front 32 rear. I personally like my tires a little stiff.

amdeutsch

I keep mine at 32F and 30R since the weight balance of the car is biased towards the front. So far, 2 tire rotations later, I have not noticed any uneven wear. I also have a good accurate analog dial gauge instead of those little stick types that most mechanics use for their quicky checks.

TNblkc230wz

I know I have a 320, but I keep my tire pressure at the hi-speed limit setting per the gas panel door which is 4 psi above normal.

HockeyPhreke

how do you rotate your tires.... 7.5 in front vs. 8.5 in back and they are directional.... so how do you manager to do that unless you all even aftermarket wheels.

DiamondNoir2K5

amdeutsch,

do you think the weight distribution is different for your 320 vs. my 230 sedan since your engine has more power (and, presumably, weighs more)?

also, does the 320 not have staggered wheels? from what i understand, i cannot rotate my tires since they are staggered (narrower in the front).

CitronC230K_03

not all WZ's have staggard wheels. 2003 and 2004 didnt. the coupes didn't up until 2005 and the C240 and C320 SS didnt have them either in 01-02.

amdeutsch

3.2 V6 versus 1.8 I4. You be the judge.

DiamondNoir2K5

I don't know by what proportion engine weight grows as a factor of liters, valves, supercharge/turbocharge, but I'm assuming from your answer that your engine does weigh considerably more.

Is there a name of this number that describes fore-aft weight distribution? Is this something I can lookup in standard tech specs for a car like on mbusa.com?